Editing Age of Darkness-Warhammer 30k/2.0 Tactics/General Tactics (section)

===Army theming===
So you've picked the army you want to build? Good. Now we can proceed to army theming, which entails building you list around a you chosen armies personality. This is actually a very simple concept but it can be given a good amount of depth and provides plenty of opportunities to create unique and clever army lists.

'''NOTE''': You '''do not''' have to make a themed army, you can just build an army and fill it with things you like (though keep it balanced). However narrative play is very big in 30k and most people do build thematic armies. In addition most armies in Heresy do play very well when built around a certain theme or narrative list.

To begin with you can very simply build you list around your chosen armies personality and known quirks, (e.g. a White Scars bike force, an Iron Warriors Artillery battalion, a Blood Angels assault army, ect...) which is a perfectly acceptable and suitable approach to build armies. Basing armies on the forces and characters from the Horus Heresy books, both the Black Library and Forge World black books, is another simple but effective way of building themed armies (e.g. building an army based around Autek Mors and his Iron Hands or a Sons of Horus Terminator army led by Abaddon).

It is also very easy to make a [[Your Dudes]] army in 30k, even if at first it doesn't seem like it. You can put an interesting spin on an army by making your own personal fluff for the force, with you own personal characters and story for them (e.g. a group of Ultramarines who have been cut off from the Legion and have been slowly whittled down until everyone left is the survivor of dozens of battles making the force a very veteran centric force). And since the Legions were so big and the Heresy was so encompassing, you can come up with hundreds of different and interesting army themes for your force, whether it is the Loyalist elements of a traitor legion, traitor elements of a loyalist legion, a chapter with specific specialisations, a company dug in to a world they were sent to garrison or a group of Black Shields who have left to do their own thing (not that those are receiving rules any time soon, or ever). The possibilities are near limitless. This does come with the caveat that the army should be connected to the Heresy in some way and just saying "yeah this is my 40k chapter, but in Heresy" is boring and going to drop you down a couple of rungs on the 30k community social ladder (but making a specialised legion chapter that are the origin of [[Your Dudes]] in 40k is very acceptable and very cool). Non space marine forces such as Militia and Cults or, to a lesser extent, Solar Auxilia (since those have strict patterns of Void Armor) are also very open to the [[Your Dudes]] treatment and are arguably more flexible to some of the more out there army themes, as Militia and Cults pretty much requires you to convert your own army and no one will get angry at a Redcoat themed Solar Auxilia army or something like that.

An important thing to note is that the existing 30k community enjoy to making balances armies, that revolve around their armies story and themes. This means it is VERY frowned upon building hyper competitive and broken armies since these are not fun to play against and will almost guarantee you won't get a game with someone. This does not mean you cannot bring strong units, but remember to keep your armies balanced and fun to play against. One unit of battery of Quad mortars in your Death Guard with Phosphex shells is strong and fluffy. 12 Quad Mortars with Phosphex shells, taking up your entire Elite choice in your White Scars Army is unfluffy and bullshit. 

Another important thing to remember is 30k is a pseudo historical so certain things cannot be used in 30k as they where not around at the time or do not fit with the style. Much like you don't use WW2 infantry in a Napoleonic era game.
*Stuff you can't use in 30k:
**Mark VII or later armour as-is (unless you're playing a loyalist legion during Siege of Terra)
**Primaris marines. For the love of god, just don't.
**Fantasy Battle/AoS stuff in general. They look bad for regular 40k conversions (without major overhauling) and look even worse in 30k.
**Post Heresy symbols such as the Crux Terminatus and 40k specific symbols.
**Purity seals. One on the pauldron or chest as an oath of moment on the squad sergeant is fine but 20 of the fucking things covering a single marine is a big no no. Unless you're a Word Bearer, but then conversions are in order since theirs lack the wax part.
**Storm bolters. No really, they were made after the Heresy and so you need to replace them with combi-bolters.
**Xenos. This is a story about humans, no smelly aliens allowed (If you convert them into humans then some of the model ranges can be used, but don't put a bunch of Eldar Guardians down and say they are Milita levies).

You can argue that Space Marines are Space Marines and that these social rules are just "gatekeeping" and "elitism" and you can continue to argue these things while you are nailed to cross for using a Stormcast model as a Space Marine Praetor, but this is how the 30k community has operated since it's formation and they will have no problems ostracizing you if you act like this (i.e. a cunt). So if things like being told to fuck off for building broken armies or using Primaris or Stormcast models is a deal breaker for you, then 30k is not the game system for you.